1. Field of the Invention
The present invention relates to a workpiece conveyor system comprising a conveyance apparatus for conveying workpieces in one direction, and a takeout apparatus for taking out workpieces which are conveyed by the conveyance apparatus.
2. Description of the Related Art
Various workpiece conveyor systems are known in the art, and these systems comprise belt conveyors or other conveyance apparatuses for conveying pluralities of workpieces, and robots or other takeout apparatuses for taking out workpieces conveyed by the conveyance apparatuses one piece at a time. In relation to this, JP-A-H05-286544 proposes a positioning system for a robot palletizer comprising a plurality of motor conveyors which convey workpieces in a predetermined conveyance direction, guide members which restrict positions of the workpieces in a lateral direction intersecting the conveyance direction, and a stopper member which stops workpieces which are conveyed along the guide members. Further, the positioning system of JP-A-H05-286544 stops the workpieces conveyed along the guide members by striking the workpieces against a flat abutting surface of a stopper member. In this regard, when a stopper member with such a flat abutting surface is used, depending on the shapes of the workpieces, the lateral faces of the workpieces are liable to come into close contact with the abutting surface of the stopper member, or the lateral faces of adjoining workpieces are liable to come into close contact with each other.
FIG. 7 is a perspective view which shows one example of a conventional conveyance apparatus which, like the positioning system of JP-A-H05-286544, comprises a stopper member which stops workpieces at a flat abutting surface. As shown in FIG. 7, the conveyance apparatus 7 of this example comprises a belt conveyor 71 which conveys a plurality of workpieces W in the direction shown by the arrow A70, and a stopper member 72 which stops workpieces W which have been conveyed up to a predetermined position at the flat abutting surface AS. Further, the workpieces W to be conveyed by the conveyance apparatus 7 of this example have triangular prism shapes and are placed on the belt conveyor 61 in the state with their bottom faces facing downward. As will be understood from FIG. 7, when workpieces W with flat lateral faces are stopped by a flat abutting surface AS, the lateral faces of the workpieces W are liable to come into close contact with the abutting surface AS, or the lateral faces of the adjoining workpieces W are liable to come into close contact with each other. As a result, the robot or other takeout apparatus is liable to grip not only a target workpiece W to be taken out but also its adjoining workpiece W, and is liable to drop the adjoining workpiece W while taking out these workpieces W.
A workpiece conveyor system which can take out workpieces stopped by a stopper one at a time in a reliable manner is therefore being sought.